A Duplex mismatch indicates a state where different Duplex modes such as, for example, a full duplex mode and a half duplex mode are set between node devices connected by means of a network.
In a case where a section is put into a Duplex mismatch, a packet in an uplink direction and a packet in a downlink direction collide with each other in that section, and a packet loss occurs.
If the amount of traffic increases in a transmission path including the section put into the Duplex mismatch, a throughput or a response is deteriorated. In this regard, however, it is difficult to detect the Duplex mismatch using simple connectivity confirmation such as a ping.
In the related art, there is disclosed a technique detecting that a section within a transmission path has been put into a Duplex mismatch, by continuously transmitting test messages.
As examples of the related art, Japanese Laid-open Patent Publication No. 2006-345224, Japanese Laid-open Patent Publication No. 2000-134216, and Japanese Laid-open Patent Publication No. 2000-224172 have been known.